TY - JOUR
T1 - The arabidopsis cellulose synthase complex
T2 - A proposed hexamer of cesa trimers in an equimolar stoichiometryw
AU - Hill, Joseph L.
AU - Hammudi, Mustafa B.
AU - Tien, Ming
N1 - Publisher Copyright:
© 2014 American Society of Plant Biologists. All rights reserved.
PY - 2014
Y1 - 2014
N2 - Cellulose is the most abundant renewable polymer on Earth and a major component of the plant cell wall. In vascular plants, cellulose synthesis is catalyzed by a large, plasma membrane-localized cellulose synthase complex (CSC), visualized as a hexameric rosette structure. Three unique cellulose synthase (CESA) isoforms are required for CSC assembly and function. However, elucidation of either the number or stoichiometry of CESAs within the CSC has remained elusive. In this study, we show a 1:1:1 stoichiometry between the three Arabidopsis thaliana secondary cell wall isozymes: CESA4, CESA7, and CESA8. This ratio was determined utilizing a simple but elegant method of quantitative immunoblotting using isoform-specific antibodies and 35S-labeled protein standards for each CESA. Additionally, the observed equimolar stoichiometry was found to be fixed along the axis of the stem, which represents a developmental gradient. Our results complement recent spectroscopic analyses pointing toward an 18-chain cellulose microfibril. Taken together, we propose that the CSC is composed of a hexamer of catalytically active CESA trimers, with each CESA in equimolar amounts.
AB - Cellulose is the most abundant renewable polymer on Earth and a major component of the plant cell wall. In vascular plants, cellulose synthesis is catalyzed by a large, plasma membrane-localized cellulose synthase complex (CSC), visualized as a hexameric rosette structure. Three unique cellulose synthase (CESA) isoforms are required for CSC assembly and function. However, elucidation of either the number or stoichiometry of CESAs within the CSC has remained elusive. In this study, we show a 1:1:1 stoichiometry between the three Arabidopsis thaliana secondary cell wall isozymes: CESA4, CESA7, and CESA8. This ratio was determined utilizing a simple but elegant method of quantitative immunoblotting using isoform-specific antibodies and 35S-labeled protein standards for each CESA. Additionally, the observed equimolar stoichiometry was found to be fixed along the axis of the stem, which represents a developmental gradient. Our results complement recent spectroscopic analyses pointing toward an 18-chain cellulose microfibril. Taken together, we propose that the CSC is composed of a hexamer of catalytically active CESA trimers, with each CESA in equimolar amounts.
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U2 - 10.1105/tpc.114.131193
DO - 10.1105/tpc.114.131193
M3 - Article
C2 - 25490917
AN - SCOPUS:84961290803
SN - 1040-4651
VL - 26
SP - 4834
EP - 4842
JO - Plant Cell
JF - Plant Cell
IS - 12
ER -